Objective:To identify the phytochemical constituents of Amorphopkallus campanulatus(A. campanulatus) tuber and to evaluate its antioxidant potential through in vitro and in vivo models. Methods:Phytochemical screening and in vitro antioxidant activities of A.campanulatus tuber n-hexane extract(ACHE) and methanolic extract(ACME) were evaluated using DPPH,hydroxyl radical,reducing power and total antioxidant capacity assays.The total phenolic and flavonoid contents were also investigated.The protective potential of two different doses of ACME(125 and 250 mg/kg) was also evaluated against thioaeetamide(TAA) induced oxidative stress in rats. Silymarin used as a standard drug control.Hepatotoxicitv was assessed by quantifying the serum levels of aspartate aminotransferase(AST),alanine aminotransferase(AIT),alkaline phosphatase (ALP) and lactate dehydrogenase(LDH).The antioxidant potential of ACME were also evaluated by the estimation of catalase(CAT),glutathione peroxidase(GPx),glutathione reductase (OR),glutathione-S-transferase(GST),reduced glutathione(GSH) and lipid peroxidation (Thiobarbituric acid reactive substances) in hepatic and renal tissues.Histopathologic changes of liver were also evaluated.Results:In vitro studies revealed that ACME has higher antioxidant and radical scavenging activity than ACHE,which may be attributed to its higher phenolic and flavonoid content.ACME significandy prevented the elevation of serum AST,ALT.ALP,LDH,and tissue malondialdehyde levels(P < 0.05).Hepatic and renal GSH.GST.GR,GPx,and catalase levels were remarkably increased by the treatment with the extract.Quantification of histopathological changes also supported the dose dependent protective effects of ACME.Conclusions:The results do suggest that A.campanulatus tuber could be considered as a potential source of natural antioxidant. Objective: To identify the phytochemical constituents of Amorphopkallus campanulatus (A. campanulatus) tuber and to evaluate its antioxidant potential through in vitro and in vivo models. Methods: Phytochemical screening and in vitro antioxidant activities of A. campanulatus tuber n-hexane extract (ACHE ) and methanolic extract (ACME) were evaluated using DPPH, hydroxyl radical, reducing power and total antioxidant capacity assays. The total phenolic and flavonoid contents were also investigated. The potential two different doses of ACME (125 and 250 mg / kg) was also evaluated as thioaeetamide (TAA) induced oxidative stress in rats. Silymarin used as a standard drug control. Hepatotoxicitv was assessed by quantifying the serum levels of aspartate aminotransferase (AST), alanine aminotransferase (AIT), alkaline phosphatase (ALP) and lactate dehydrogenase (LDH). The antioxidant potential of ACME was also evaluated by the estimation of catalase (CAT), glutathione peroxidase (GPx), glutathione Reductase (OR), glutathione-S-transferase (GST), reduced glutathione (GSH) and lipid peroxidation (Thiobarbituric acid reactive substances) in hepatic and renal tissues. Histopathologic changes of liver were also evaluated. Results: In vitro studies revealed that ACME has higher antioxidant and radical scavenging activity than ACHE, which may be attributed to its higher phenolic and flavonoid content. ACME significandy prevented the elevation of serum AST, ALT.ALP, LDH, and tissue malondialdehyde levels (P <0.05) .Hepatic and renal GSH.GST.GR, GPx, and catalase levels were remarkably increased by the treatment with the extract. Quantification of histopathological changes also supported the dose dependent protective effects of ACME. Conclusions: The results do suggest that A. campanulatus tuber could be considered as a potential source of natural antioxidant.